I'll bet dollars to donuts that you'll get a ton of different answers, but IMHO, it doesn't matter from an SEO/SERPS standpoint. Incoming links, content, and domain age are what matter when it comes to ranking on the search engine.
HOWEVER - you will likely get a better clickthrough rate by consumers on the .com because it is perceived as a more credible extension.
There are always exceptions -- ie: winelibrary.tv and the phenom that is Gary Vay-ner-CHUCK, but that's because he built his brand - not because of his domain.